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I am developing a little library and probably an app to download/process Sentinel-2 data from AWS from within browsers. It seems that I can not make any Range requests to the server. I get a CORS error. Example code:


let res = fetch(

  'https://sentinel-s2-l1c.s3.amazonaws.com/tiles/32/U/MA/2017/4/30/0/B01.jp2',

  {

    method: 'GET',

    mode: 'cors',

    headers: {

      Range: 'bytes=0-100'

    }

});

Any chance that you will enable Range requests on AWS? I did a little research and as far as I understand you might need to enable “access-control-allow-headers:Range”.


Thank you, Jan

Hi Jan,


Should be working now.

Thanks a lot Primoz, range requests do work now!


Just one other tiny thing: I am doing a HEAD request to get the content-length of the image. That seems to be disabled as well:


Access-Control-Allow-Headers Content-Length

Access-Control-Expose-Headers Content-Length

GET was the only request that had CORS response headers. I’ve added HEAD aswell. It should work now.

Hi Primoz,


Thanks, but I still get this error:


Refused to get unsafe header "Content-Length"

200 "image/jp2" null

Any idea?


Test: (fetch does not work either - seems fetch does not expose content-length at all)


let req = new XMLHttpRequest();

    req.onload = () => {

      if (req.status === 200) {

        console.log(

          req.status,

          req.getResponseHeader('Content-Type'),

          req.getResponseHeader('Content-Length')

        )

      } else {

        console.log(req.status);

      }

    };

req.open('HEAD', 'https://sentinel-s2-l1c.s3.amazonaws.com/tiles/32/U/MA/2017/4/30/0/B01.jp2');

req.send();

Sorry to keep bugging you with this issue. I did some research and it seems that for s3 you need to explicitly allow “Content-Length” e.g.


<?xml version="1.0" encoding="UTF-8"?>

<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">

    <CORSRule>

        <AllowedOrigin><!-- insert your origin here --></AllowedOrigin>

        <AllowedMethod>GET</AllowedMethod>

        <AllowedHeader>Range</AllowedHeader>

        <MaxAgeSeconds>3000</MaxAgeSeconds>

        <ExposeHeader>Accept-Ranges</ExposeHeader>

        <ExposeHeader>Content-Range</ExposeHeader>

        <ExposeHeader>Content-Encoding</ExposeHeader>

        <ExposeHeader>Content-Length</ExposeHeader>

        <AllowedHeader>Authorization</AllowedHeader>

    </CORSRule>

</CORSConfiguration>

source: https://github.com/mozilla/pdf.js/issues/4530


I can get “content-length” with a http.request in node.js but no chance in the browser.

Hi Jan,

I’ve explicitly exposed the content-length header for HEAD requests and tested it. Should work now.

👌 Does work now!

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